Various electro-mechanical means have been used in the prior art to hold a missile in an unarmed state while it was being launched and to arm it after a specific interval of time. The problem with prior art devices was that the isolation switching circuitry, used to isolate the warhead initiating or arming circuitry from the missiles power source, frequently would inadvertently function upon receipt of extraneous electrical signals. The problem with use of DC operated switches or use of standard stepping motors was that they would become operable because of receipt of a spurious electrical signal or could function because of a single short circuit thereby causing the missile to be placed in the intolerable condition of fail-arm. Use of multiphase motors to actuate the enabling switches of a missile is a problem in missile applications because of low holding and operating torque. In missile application, the high stress environments due to spin, pitch, yaw and setback forces can easily overcome the low holding and operating torque of multi-phase motors thus causing a malfunction.